Carriers have been fighting sims for years because it makes it too easy to switch carriers. I think TMobile is the first one out of the gate to do this. You can download their app, try the service for a month or two by activating the esaim. If you like it, you can transfer your service right from the app.

Not having to talk to sales reps or go to stores is a big win for customers. Granted, this is mostly hypothetical at this point but it is coming.